Question

animation learning module: dna replication
read the overview below and complete the activities that follow.
this animation learning module is designed to increase your understanding of basic dna structure. first, you will answer basic questions related to this topic. then, you will actively engage with an animation by answering questions as you watch. finally, you will be given some follow - up concept check questions to make sure you understand the concept fully.
concept check #1

1. the three basic parts of a nucleotide are

○ carboxyl group, deoxyribose sugar, nitrogenous base
○ phosphate, hexose sugar, nitrogenous base
○ phosphate, deoxyribose sugar, nitrogenous base
○ phosphate, deoxyriboses sugar, glycerol

1. which of these are base - paired correctly?

○ c - t
○ g - t
○ c - a
○ t - a

1. the two strands of dna are joined to each other or held together by

○ covalent bonding
○ hydrophilic interaction
○ van der waals forces
○ hydrogen bonding

Explanation:

1. A nucleotide consists of a phosphate group, deoxyribose sugar (in DNA), and a nitrogenous base. Carboxyl group is not part of a nucleotide. Hexose sugar is not deoxyribose. Glycerol is not part of a nucleotide.
2. In DNA base - pairing, adenine (A) pairs with thymine (T) and cytosine (C) pairs with guanine (G). So, T - A is correctly base - paired.
3. The two strands of DNA are held together by hydrogen bonds between the nitrogenous bases. Covalent bonding is within a single strand (phosphodiester bonds). Hydrophilic interaction and van der Waals forces are not the main forces holding the two strands together.

Answer:

1. phosphate, deoxyribose sugar, nitrogenous base
2. T - A
3. hydrogen bonding